module ActiveRecord
  class AttributeSet
    # Attempts to do more intelligent YAML dumping of an
    # ActiveRecord::AttributeSet to reduce the size of the resulting string
    class YAMLEncoder
      def initialize(default_types)
        @default_types = default_types
      end

      def encode(attribute_set, coder)
        coder['concise_attributes'] = attribute_set.each_value.map do |attr|
          if attr.type.equal?(default_types[attr.name])
            attr.with_type(nil)
          else
            attr
          end
        end
      end

      def decode(coder)
        if coder['attributes']
          coder['attributes']
        else
          attributes_hash = Hash[coder['concise_attributes'].map do |attr|
            if attr.type.nil?
              attr = attr.with_type(default_types[attr.name])
            end
            [attr.name, attr]
          end]
          AttributeSet.new(attributes_hash)
        end
      end

      protected

      attr_reader :default_types
    end
  end
end